Is RVNormal the right code to use?

I'm trying to create a new dataset where the avg age for that new dataset = x. I thought RV.NORMAL was the right way but it only gives me a new variable where the avg of that new variable is x. How can I base it off of the age variable that I already have in my dataset? So there would less records in my new dataset since the avg age I want is different than my whole dataset.